Here in Italy, which entered the war in 1915 on the side of Britain and France, the focus will be in the very north of the country, in places like Trento, where bitter mountain fighting cost more than half a million Italian lives.

On Monday in Britain there will be a service at Glasgow Cathedral the morning after the close of the Commonwealth Games, followed by a vigil at Westminster Abbey.

Across the Channel, at St Symphorien, near Mons in Belgium, leaders of nations that were on both sides of that conflict will gather in a beautiful cemetery that includes the graves of Allied and German war dead. Similar services will be held in cities, country towns and cemeteries around the world, including Australia.

On April 25th next year we will commemorate the centenary of the Allied landings at Gallipoli in 1915. People will gather at hundreds of dawn services at ANZAC Cove in Turkey; around Australia and New Zealand; in the steaming heat of Papua New Guinea; in the morning chill of a Flanders field; at Villers Bretonneux in France; at Souda Bay in Crete; here at the Rome War Cemetery, and at similar ceremonies around the world.

For Australians and New Zealanders, Gallipoli has a special significance. On ANZAC Day we honour a unique relationship between both countries forged in mud and blood. It was this conflict that helped shape our characters and define our identities as new nations, as well as enshrine a bond between us that can never be broken.

In April the New Zealand High Commissioner to the United Kingdom, Sir Lockwood Smith and I visited Gallipoli with the Commonwealth War Graves Commission. We crossed the Dardanelles by ferry and drove to ANZAC Cove, playing songs like “The Band played Waltzing Matilda” and “Maori Battalion” in the car.

Without crowds, speeches and hymns there was a quiet, poignant beauty to a glorious coastline with towering hills, a sea of deepest blue and beaches that reminded us of home. Not the bloodstained hell that it was 99 years ago. The only sound we heard was the gentle lapping of the waves on the shore.

We visited cemeteries that were once battlefields, our soldiers buried where they fell, but now ablaze with irises, pink flowering Judas trees and hedges of rosemary. At the Nek we stood on a ridge where four waves of Australian Light Horsemen were mown down. It was where Charles Bean wrote that “the flower of the youth of Victoria and Western Australia fell”. At Beach Cemetery we paid our respects at the grave of John Simpson, the digger with the donkey, who cared for his mates.

Further down the Peninsula we visited a cemetery where 10,000 of our French allies were buried, and a memorial at Helles Point remembering the 21,000 British as well as soldiers from India and Newfoundland who died there.

But more than anything it was the inscriptions on the headstones that are fused in my memory. Some said “died for God, King and Country”, but it was the more personal, the more intimate, that were most powerful. “My darling only son”, or “From your wife and four young children”, or “left us a boy, died a man”, or the last words of a dying Aussie solder to the mate who was holding him in his arms “God bless you, Cobber”.

Most of all I will remember the simple, plaintive cry of a mother, with her inscription “We miss you at home”, a sentiment of sacrifice experienced in recent years by so many mums, partners and kids of our soldiers lost in Afghanistan.

So at dawn services each ANZAC Day, Aussies and Kiwis say a quiet and humble thankyou to mark the everlasting companionship between the living and dead. And each year we are moved when the Turkish Ambassador recites the words of Ataturk now engraved on a memorial at ANZAC Cove.

Those heroes that shed their bloodAnd lost their lives. You are now lying in the soil of a friendly country.Therefore, rest in peace. There is no difference between the JohnniesAnd the Mehmets to us where they lie side by sideHere in this country of ours,You, the mothers,Who sent their sons from far away countriesWipe away your tears, Your sons are now lying in our bosomAnd are in peaceAfter having lost their lives on this land they haveBecome our sons as well.

The World War One ceremonies will continue in 2016 at the Somme, a battleground which alone claimed more than a million lives. Among them the writers, artists and musicians, the great engineers and doctors, the farmers, factory workers, the husbands and fathers who were not to be.

They will not be forgotten. We will sing the hymns and read their names engraved on memorial walls and headstones; the lost company of cheerful mates.

The statistics tell a stark story. Staggeringly, the total number of military and civilian casualties in World War One was more than 37 million, including 16 million dead and 20 million wounded. A generation of young men were lost.

The impact on countries with small populations was also immense. Between 1914 and 1918, 38.7 percent of the total male population of Australia, aged between 18 and 44, fought with a casualty rate of 65 percent, the highest of any country.

But this year the commemorations are not only focused on the Great War.

In May, shortly after arriving in Italy Sasha and I attended the services commemorating the 70th anniversary of the Battle of Monte Cassino.

The Polish service was deeply moving. More than 1000 brave Poles died storming the German stronghold in the ruins of the once glorious 11th century abbey at the top of the mountain.

At the cemetery, high on the towering hillside and close to the rebuilt abbey, a Polish scout or guide stood behind each headstone, a reminder of the sacrifice that helped build their future. The inscription on the memorial is particularly poignant.

For our freedom and yours We soldiers of Poland Gave Our soul to God Our life to the soil of Italy Our hearts to Poland

There is also a message to visitors: “Passer-by, go tell Poland that we have perished obedient to her service”.

We also joined the New Zealand Governor-General, veterans and their families at the cemetery where 500 Kiwi soldiers are buried, many of them members of the famed Maori Battalion. We watched the spirited Haka challenge to Prince Harry and were moved at the sight of one old soldier searching for, finding and caressing the headstone of the brother who had fought beside him there in 1944.

At the UK ceremony the following day I thought of my own father who had fought in Italy with the British Army. At the Commonwealth Cemetery I was once again reminded of the importance of the word “ally”, so powerfully reinforced by the inscription on the Australian War Memorial at Hyde Park Corner in London: “Whatever burden you are to carry, we also will shoulder that burden”. It was a message from Australia to Churchill in 1940, when Britain didn’t quite “stand alone” because there were Aussie and Kiwi pilots in the skies over Kent and Sussex defending London.

And we must never forget the Eighth Army, in all its multicultural strength and diversity, who, on its long march across the deserts of North Africa and from one end of Italy to the other, took a step each day closer to home and to victory.

In June, of course, we remembered that 70 years ago on D-Day, the largest armada history has ever seen, left Britain in an operation that was as epic in scale as it was in aspiration.

Their purpose could not have been clearer. Europe was enslaved by the greatest tyranny. Proud nations were in chains. Millions were dying in camps such as Auschwitz, Dachau and Bergen Belsen.Civilisation, itself, was in peril.

Their mission wasn’t simply to storm the Normandy beaches. It was to free a continent.

And the Allies could not have prevailed in Normandy without the intelligence coming from Bletchley Park where 9,000 people worked undiscovered in three shifts every day, year after year, breaking the codes that helped shorten the War, saving countless lives.

All these events were inter-connected at a time when history itself appeared to be racing.

There could be no D-Day unless the RAF, whose fighter pilots alongside those from Australia, New Zealand, Poland, Czechoslovakia and Canada, had not won the Battle of Britain. There could be no VE-Day without D-Day. No VE-Day without the massive sacrifice of millions of Soviet troops and citizens. No VP-Day without the bravery of our American friends at Midway, Guadacanal and Okinawa and alongside Australian diggers in the jungles of New Guinea.

For those of us who had parents and grandparents who served their countries in both World Wars, the ceremonies will have great personal meaning.

Last year at Westminster Abbey I attended a service to commemorate the 73rd anniversary of the Battle of Britain. I will always remember the faces of those surviving pilots as they looked up to see a Spitfire and Hurricane flying in close formation over Big Ben.

Today we look back to generations that possessed a quality of spontaneous decency and shared sense of duty. They were prepared to give everything, including their lives, to the next generation. We remember their talents, their promise, the years never spent with their children, their spouses or their sweethearts. They endured bereavement, privation, smashed cities, and prolonged separations from loved ones, that are unimaginable to us now.

In a time of terrorism, when the enemy is often unknown and unseen, we honour not only those who have fallen but also those who continue to bravely serve us in conflict zones and in peacekeeping operations around the world.

So, as we honour a century of sacrifice we will remember our fallen comrades as the best of our breed, the saviours of all we cherish and the architects of who and what we are.